Improvement in automatic dental plugging-instruments



UNITED STATES PATENT CFFTGE.

GEORGE SNOW AND THEODORE Gr. LEWIS, OF BUFFALO, NEW' YORK. Y

IMPROVEMENT IN AUTOMATIC DENTAL PLUGGING-INSTRUIMENTS.

Specification forming part of Letters Patent No. 79,270, dated June 23, 1868'.

laccompanying drawings, making a part of this specification, (Division No. 2,) in which- Figure I is an elevation of the instrument;

Fig. II. is Va longitudinal section, showing all the working parts as contained within the case forming the handle, as claimed in this division. Fig. III is across-section on line 12ofFig.I.;4 f I The nature of this invention, so far as the same is describedand claimed in this division, relates to constructing a plugging-instrument so that its automatic operating parts shall be contained within the tube or case forming the handle of the instrument.

A represents the upper section, and A the lower section, of the case. It is in the form of a tube or hollow cylinder, and the lower section has a hollow plug, which screws into the upper section, as shown at a2.

B is whatwecall the tool-holder. Itpasses entirely through the lower section of the case, projecting below to receive the plugging-tool C, and above and into the upper section to receive the lifting-bar D at its upper end. A hole is made through its upper end to receive the bent end 0r hook of the lifting-bar, as shown at d1.

The plugging-tool screws into the lower end, as shown at c'. A spiral spring, E, is placed around the tool-holder and within the lower section of the case, to effect its proper receding' movement immediately after a blow has been struck. This spring rests upon a shoulder, el, formed on the tool-holder, and between it and a shoulder, e2, formed within the case.

F represents the hammer, which is placed wholly within the upper section of the case. A shoulder, j", is formed on the hammer for the spring to rest against. A screw-cap, II, is put upon the top of the clase, and an adjusting-stopper, I, passes through it, which may be raised to the height shown in Fig. II for a light blow, or loweredfor a heavy blow.

A pin, J, passes through the stem of this stopper, which, when the the stopper is turned in one position, will catch under the screwcap, holding the stopper down upon the spring, and ,compressing it to. give a heavy blow; and, when turned in another position, the pin will pass out ofthe screw-cap through a slot, and allow the stopper to return to the position shown in Fig. II, thereby 'allowing the spring to expand lina manner to cause the hammer to strike a lighter blow. y ,f

A groove, K, is formed in the hammer, in which are placed the stops or catches L L'. A releasing-wedge, M, is placed onthe inside ofthe upper section of the case, which is held stationary andin placeby the screwn. This wedge projects into the groove, and serves as a `guide to the up-and-.down movements of the hammer,

the groove being deep` enough `to allowthe stops to pass .freely under the wedge. rIhe upper part of the lifting-bar D also vlies in this groove. Y

The iiat spring d2, which is connected to the lifting-bar, presses against the inside of the case, and serves to keep this lifting-bar pressed down to the bottom of the groove, so that the notch cl3 will engage with one of the stops or catches, as shown in Fig. II, when the bar is moved up by the tool-holder, and therebyg carry the hammer upwardly until the liftingbar is disengaged by passing over the incline of the releasing-wedge, and the hammer therethe other slot works over the feather O, thereby v preventing the tool-holder from turning, and keeping the parts in position.

Now, when the ring is turned to the left, so as to place the screw S in the position shown in Fig. III, the outward thrust of the toolholder will be arrested by this screw, so that the lifting-bar will engage with the second stop L', and thereby lessen the force of the blow by lessenin'g the distance through which the hammer falls. When the ring is turned to the right, so as to bring the screw S in the space between the two parts of the feather, then the slot in the collar U will pass over the screw, it being in line with the feather, so that the outward thrust or receding movement of the tool-holder will be continued to its utmost limit, and the lifting-bar will engage with the first stop L, as shown in Fig. I.v

Now, the greater distance is obtained between the hammer and the head of the toolholder, so that when the parts are again moved up and the hammer disengaged it will fall through a greater distance, and hence increase the force of the blow. rlhe feather O will limit the 'fall of the hammer, and the hammer will rest upon it when the blow is given, so that the tool-holder will be enabled to recede from it and gain position for a new blow.

Thus, by means of the arrangement of these last-mentioned parts, as described, we are enabled to vary the force of the blow in two degrees by varying the distance through which the hammer falls; and, by means ofthe adjustable stopper or screw-cap at the top, we are also enabled to vary the force of the blow in two degrees, byiincreasing and diminishing the tension of the spring G; 4and thus we obtain blows of four different degrees of power, at the will of the operator.

The operator holds the instrument in his hand, and presses the plugging-tool against the iilling of the tooth, which becomes a resisting object. A moderate pressure upon the instrument will cause the tool-holder to pass within the case, imparting its movement to the lifting-bar and .to the hammer, until the lifting-bar passes over the incline of the wedge and releases its hold upon the catch, and then the hammer is driven down by the force of the spring G, striking a blow of more or less power upon the head of the tool-holder, the force of the blow being graduated by the conditions before described.

When the blow is given the pressure of the hand upon the instrument is lessened, so that the spring E will instantly act and cause the tool-holder to recede to its eXtreme limit for the lifting-bar to take a new hold upon the hammer, and thus the blows may be repeated as often as the operator desires.

All the operating parts of the instrument are within the case forming the handle, and out of sight and out of the way, so thatA the instrument may be used without impediment, and its beauty and symmetry preserved.

Having now fully described the construction and operation of our improved plugginginstrument, so far as the same has reference to the improvement claimed in this division, what we claim as our invention, and desire to secure by these Letters Patent, is-

A plugging-instrument having all its autor matic operating parts contained within the case forming the handle of the instrument,

substantially as described.

- GEO. B. SNOW.

-' THEODORE G. LEWIS.

Witnesses:

E. B. FoRBUsH, B. H. MUEHLE. 

